Kansas City Chiefs head coach Andy Reid is in a stable condition and "doing well" after he was transported to hospital following Sunday's defeat to the Los Angeles Chargers.

Reid was on the sidelines as the Chiefs suffered consecutive NFL losses, beaten 30-24 by visiting AFC West rivals the Chargers at Arrowhead Stadium.

The 63-year-old Super Bowl-winning coach, however, fell ill and left the stadium in an ambulance.

"Head coach Andy Reid felt ill at the conclusion of the game," the Chiefs said in a statement amid reports the veteran was treated for dehydration.

"He was evaluated by our medical staff in the locker room, and [as] a precaution, was transported to The University of Kansas Health System for further evaluation. Coach is doing well, currently resting and in stable condition."

Reid did not address the media as a result, with assistant head coach Dave Toub speaking to reporters after the Chiefs fell to 1-2 to start the season.

The Chiefs – two-time defending conference champions – have a losing record for the first time since Week 11 of the 2015 season.

"This is unusual for us, to be honest," Toub said. "It's a little bit of a crossroads for us, I think. We've got great leadership and our guys are going to battle back.

"Our guys are going to battle back strong. We're going to have a great week of practice and clean it up. We've got to clean up the game, clean up the turnovers, execute on the offensive side of the ball, create turnovers on defense and stops on defense and play solid special teams. We'll get back on track."